Re: [Qemu-devel] [PATCH] Inter-VM shared memory PCI device

[Paul Brook]

> On 03/10/2010 07:41 PM, Paul Brook wrote:
> >>> You're much better off using a bulk-data transfer API that relaxes
> >>> coherency requirements.  IOW, shared memory doesn't make sense for TCG
> >>
> >> Rather, tcg doesn't make sense for shared memory smp.  But we knew that
> >> already.
> >
> > In think TCG SMP is a hard, but soluble problem, especially when you're
> > running guests used to coping with NUMA.
> 
> Do you mean by using a per-cpu tlb?  These kind of solutions are
> generally slow, but tcg's slowness may mask this out.

Yes.

> > TCG interacting with third parties via shared memory is probably never
> > going to make sense.
> 
> The third party in this case is qemu.

Maybe. But it's a different instance of qemu, and once this feature exists I 
bet people will use it for other things.

Paul